Read the full writeup at http://www.fiorixxx.com/2016/10/06/h4ck1t-ctf-2016-north-korea-fucking-russian-programmers-100pts/

Original writeup (http://www.fiorixxx.com/2016/10/06/h4ck1t-ctf-2016-north-korea-fucking-russian-programmers-100pts/).